Mineral material, for example rock is gained from the earth for crushing by exploding or excavating. Mineral material can also be natural and gravel or construction waste. Mobile crushers and stationary crushing applications are used in crushing. An excavator or wheeled loader loads the material to be crushed into the crushers feed hopper from where the material to be crushed may fall into the crusher or a feeder moves the rock material towards the crusher.
A mineral material processing plant comprises one or more crushers and/or screens and possibly other apparatuses such as conveyors. A processing plant may be stationary or mobile. Particularly mobile processing plants are used in urban environment in handling of recyclable material such as construction waste.
Capacity of a processing plant is aimed to be used economically fully so that the crusher is loaded continuously with a high crushing power and simultaneously the used crushing power is directed for producing the planned product distribution. Interruptions in the crushing event reduce efficiency. Also the starting of a processing plant is a time consuming task that further impedes the efficient exploitation of the plant's capacity.
Mineral material processing plants are used also in extreme, for instance in very cold, circumstances wherein the processing plant may be required to be kept in operation also when the material to be handled is not fed into the plant. Different laws and administrative orders also regulate the use, starting and running of the processing plants.
It is an object of the invention to provide a mineral material processing plant the bringing of which into process operation is quick and safe. It is an object of the invention to provide a processing plant that can be kept in operation energy-efficiently. It is an object of the invention to enable an effective crushing or other processing time as long as possible.